'7 Boxes (7 Cajas)' (unrated)

Victor (Celso Franco) is a scrappy 17-year-old who makes a living at an open-air market in Paraguay helping customers carry their bags to their cars in his wheelbarrow. The bagboy business is competitive — Nelson (Victor Sosa), Victor’s chief competitor, desperately needs money to buy insulin for his infant son — and directors Juan Carlos Maneglia and Tana Schembori use time-lapse photography and long tracking shots that sends us hurtling through the streets of the bazaar at rib-tickling speed, turning the place into a seemingly endless maze of shops and markets bustling with sound and energy (you can practically smell the fresh fish and fruits).

After Victor catches his first glimpse of a cellphone featuring a camera (the film is set in 2005), he’s transfixed by watching himself on video and decides he must have one of his own. But cellphones are expensive, and Victor earns spare change at best. So he agrees to transport seven wooden boxes for a shady restaurant owner to a specific location and wait for instructions, and he’ll get paid $100 in U.S. currency — enough for a super-deluxe phone with all the trimmings. But there are rules. He must not look inside the boxes. He must not let the police inspect the packages. And most of all, he had better not lose them.

The screenplay for 7 Boxes is a beautiful example of how to craft a tense and increasingly complex thriller out of a simple scenario. Victor’s assignment seems easy enough, but one of the boxes is almost immediately stolen, and Nelson, who knows what the kid is up to, is intent on stealing the packages and carrying out the mission himself. Everything in the movie is there for a reason, such as a seemingly pointless subplot involving Victor’s sister, who works at a Chinese restaurant with a pregnant woman about to go into labor at any moment.

They figure prominently into the plot as the story develops with dizzying speed, at time recalling the furious energy of Run Lola Run. The film is filled with surprises — you may think you know what’s inside the boxes, but you don’t — and the directors inject the picture with great style, making us as anxious as Victor as a seemingly inescapable noose begins to tighten around the kid. Unlike in most thrillers of this kind, you’re not always sure he will find a way out: 7 Boxes doesn’t follow any Hollywood formulas, building its own brand of high-speed suspense marked by pitch-black humor and breathtaking twists.